Dinosaur VaultEvery known dinosaur
Gallimimus, Late CretaceousNemegt Formation, Mongolia · named 1972
See more pictures

Gallimimus

GAL-ih-MY-mus

"chicken mimic"

Lived
72 to 66 million years ago, Late Cretaceous
Diet
Omnivore
Length
about 6 m (20 ft)
Weight
about 440 kg (970 lb)
Group
Theropods, Ornithomimidae
Found in
Mongolia
Named by
Osmólska et al. 1972

Size comparison

To scale

Where its fossils were found

The evidence

Today

27 finds

70 million years ago

Map: C. R. Scotese, PALEOMAP

Habitat

Its Nemegt home included river channels and floodplains. Saurolophus, Deinocheirus and Tarbosaurus lived in the region.

Field notes

About Gallimimus

What it was like

Gallimimus was a slender, long-legged theropod built for speed, with a small toothless head, a long neck, and a beak-like mouth. It grew to about 6 meters (20 feet) long and weighed around 440 kilograms (970 pounds), making it the largest known member of its family.

Its arms were short with three clawed fingers, and its long hind legs suggest it could run fast to escape predators. Gallimimus was probably an omnivore, eating small animals, plants, or both, though scientists still debate exactly what made up its diet.

Its world

Gallimimus lived in what is now Mongolia between about 72 and 66 million years ago, during the Late Cretaceous. Its fossils come from the Nemegt and Baruungoyot formations.

It shared its habitat with the armored Tarchia, the feathered Avimimus, and predators such as Velociraptor and Tarbosaurus. The huge, long-armed Deinocheirus, a distant relative, lived in the same region.

How it was found

Osmólska and colleagues named Gallimimus in 1972, based on fossils collected in Mongolia. About 27 finds of the genus are known today, including skeletons of different ages, which has helped researchers study how it grew.

Field gallery

More views of Gallimimus

Scenes reconstructed from the available fossil evidence.

Gallimimus in its habitat, photo 1

1 of 7

Lived alongside

Found in the same rock formations

A rock formation can hold fossils laid down millions of years apart, so not every animal here met Gallimimus.

The evidence

The science behind Gallimimus

Which parts of the picture come from its own bones, and which come from its relatives.

From its own fossils

  • Skeletons show a small, toothless skull, a long neck, long hindlegs and a balancing tail.
  • The hands had three clawed fingers and faced inward.
  • A skull preserves traces of the horny covering of its beak.

Borrowed from relatives

  • Much of the body is known from its own skeletons.
  • A feathered body and feathered arms are inferred from Ornithomimus, which preserves feathers.

Still unknown

  • Exactly what it ate.
  • The color and arrangement of its feathers, especially in young animals.
  • Whether it lived in lasting groups or cared for its young.

Often drawn wrong

  • Toothed jaws replace its toothless beak.
  • Palms facing the ground give its hands a movement they could not make.
  • Bare arms overlook the feathers inferred from Ornithomimus.

Discovery timeline

  1. 1972Named itOsmólska, Roniewicz & Barsbold
  2. 2001How it fedNorell, Makovicky & Currie
  3. 2005How it fedBARRETT
  4. 2012Close relativeZelenitsky et al.
  5. 2014Same rocksLee et al.

Key papers

The research behind what we know of Gallimimus

Close relatives

Other members of Ornithomimidae

Sources: Wikidata